package com.pay.modules.wxpay.util;

import org.apache.commons.lang3.StringUtils;

import java.security.MessageDigest;

/**
 * MD5加密
 */
public class MD5Util {

	private static String byteArrayToHexString(byte[] b) {
		StringBuffer resultSb = new StringBuffer();
		for (int i = 0; i < b.length; i++) {
            resultSb.append(byteToHexString(b[i]));
        }
		return resultSb.toString();
	}

	private static String byteToHexString(byte b) {
		int n = b;
		if (n < 0) {
            n += 256;
        }
		int d1 = n / 16;
		int d2 = n % 16;
		return hexDigits[d1] + hexDigits[d2];
	}

	public static String MD5Encode(String origin, String charsetName) {
		String resultString = null;
		try {
			resultString = origin;
			MessageDigest md = MessageDigest.getInstance("MD5");
			if (StringUtils.isBlank(charsetName)) {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
            } else {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetName)));
            }
		} catch (Exception exception) {
		}
		return resultString;
	}

    private static final String[] hexDigits = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};
}
